Former for cartons



March 3, 1953 'r. ROWLANDS FORMER FOR CARTONS Filed June 5, 1951 III III lllll'l'l-IIII'IIIIIIll-l.

INVENTOR MW @MMWi- Patented Mar. 3,,1953

FORMER FOR CARTONS Tom Rowlands, Stoke Bishop, Bristol, England Application June 5, 1951, Serial No. 229,894 In Great Britain June 9, 1950 1 Claim.

This invention concerns improvements in or relating to formers for cartons and more particularly formers for carton bodies which are of substantially fiat-sided cross-section as explained below. The expression substantially flat-sided" is used here to include bodies whose cross-section is triangular, square, rectangular or polygonal. The expression also includes figures of the simpler shapes having rounded corners. For example a substantially rectangular carton body may have two pairs of parallel sides joined by circular arcs each subtending 90. Usually triangular cartons are of equilateral cross-section and a hexagonal carton is a regular hexagon in cross-section for obvious advantages in packing. Carton bodies of these various shapes will be referred to for convenience as carton bodies as specified.

Carton bodies as specified may be formed into cartons by inserting ends of the same shape as the interior of the body, said ends being dished or flanged, and after the ends have been inserted, turning over the material constituting the end of the body to engage the flanged parts. A complete carton of this nature will be referred to for convenience as a carton as specified. In the process, adhesive is used to stick the flanges to the interior of the body and the turned over parts of the body to the flanges. In order to facilitate the turning-over, the material forming the body is creased on suitable lines and the former over which the body is made is grooved to accommodate these creases whether they are made while the material is flat or whether they are made as part of the body-forming operation. As it is necessary to strip the finished'body from the former by moving the body lengthwise on the former it will be seen that the creases hinder this operation by catching in said grooves.

Cartons as specified having rounded corners lend themselves to this process of manufacture because the rounded corners enable the flanged end to be pressed out of a single piece of material by a drawing operation, provided the radius of the corner" is large enough. The invention may also be useful where the bodies are indented other than by creases as referred to above, and any such indentations are hereafter termed creases or the like.

According to the present invention there is provided a former for carton bodies as specified and grooved to accommodate creases or the like in the carton material, wherein the sides of the former are each shaped to the form of a shallow concave surface the concavity being transverse to the length of the former and of such depth that the cross-section of a body formed by wrapping material about the former in close engagement with the surface thereof is of such longer perimeter than that of a figure formed by joining the extremities of the concave arcs by chords that the carton, when free to expand so that its sides flatten, is sufficiently larger than the former that the creases in the material will clear the grooves in the former and the carton can be slid off the former.

One construction of former will now be described by way of example with reference to th accompanying drawings in which:

Figure 1 is a plan of a former.

Figure 2 is a top view of Figure 1.

The carton body for which the former illustrated is used has four sides consisting of two parallel pairs, the sides whereof are spaced 2% apart. The ends of the flat parts of the sides are joined by circular arcs of about inch radius. The body is thus a carton body as specified.

The former l on which the body is made by wrapping the material about the sides thereof and securing the ends of the material by a seam running lengthwise of the body, is of much the same shape as the interior cross-section of the body but the surfaces of the former corresponding to the flat sides of the carton are formed as concave surfaces, as indicated by the arrow 2, Figure 2. The arc of the concavity is normal to the length of the former and, for a particular body having sides 0.018 inch thick, and wherein the creases are formed by depressing the material into grooves 0.012 deep, the height of the chord of the arc may be 0.050 inch. Towards its ends the former has grooves 3 running round its perimeter and normal to the length of the former. These grooves register with creases made in the body material. These creases may be made while the material is flat or during the actual bodyforming, according to the nature of the process used. If the creases are made during forming scoring rollers such as the one shown at 4 are used. The above dimensions of the concave surfaces of the former are sufficient to ensure that the perimeter of the carton, when free to expand, is sufficiently larger than the former that the creases are cleared from the grooves in the former and the carton can be slid endwise off the former.

Usually the wrapping is made by a winding operation, the former being rotated to wind the material around it and the latter being engaged by a pressure roller 5 or other suitable device to press the material tightly against the surface of the former, but the nature of the process employed is not pertinent to the invention.

The manufacture of a carton body in this way, that is, on a former with concave sides, hasxan advantage in that the sides tend to remain fairly flat when the body is released from the former.

What I claim as my invention and desire to secure by Letters Patent is:

A former for carton bodies as specified and grooved to accommodate creases or the like in 10 ff th f r er,.

the carton material, wherein the sides of the former are each shaped to the form of a shallow concave surface the concavity being transverse to the length of the former and of such depth TOM ROWLANDS.

No references cited. 

